This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. IMPAACT protocol that utilizes QHPV - P1047 is a closed protocol that is investigating the safety and immunogenicity of QHPV in HIV-infected girls and boys, age 7 to 12 years of age. This study was a placebo-controlled trial that compared a recommended three dose schedule of QHPV in one study arm (Arm A) with an arm that received placebo (Arm B). At 96 weeks after study entry the QHPV recipients (Arm A) received a fourth dose of QHPV and were subsequently evaluated for evidence of an anamnestic antibody response. Also at 96 weeks the previous placebo recipients (Arm B) began the same three dose schedule of QHPV that was administered in Arm A. Thus, two different cohorts are currently available for future evaluation. In summary, we seek to determine the long-term durability and kinetics of the vaccine-induced HPV-type-specific antibody and CMI responses in HIV-infected children that were, and are being, immunized in P1047. These subjects are a unique cohort that will allow us to approach this specific clinical issue.